Studies are continuing on the environmental factors which ameliorate genetic diabetes in the Chinese hamster including: 1) the effect of synthetic diets differing qualitatively in fat components and, 2) the effect of continuous long-term insulin provided by implanted "mini-pumps". Investigation of the interrelation of calcium with insulin and glucagon secretion is also being extended by coordinating hormone release and 45Ca uptake and efflux with changes in islet regulators.